The Industrial Raspberry Pi Forum

Hi Nicolai, thanks for your response.
It is confusing, because in the latest schematics there is a 120 Ohm resistor that is driven by RS485_TERMINATION (GPIO41)

downloads -> schematics -> RevPi Connect -> RevPi Connect S:
https://revolutionpi.com/fileadmin/down ... onnect.zip (BG0187R06_SchematicWeb.PDF)

Am I looking the at the wrong schematics? Is it the other file in the zip? (BG0188R04_SchematicWeb.PDF)

Anyway, good to know I have to use external resistors.

I think you're mixing PiBridge and external RS485. The external RS485 port is shown on page 3 of BG0188R04_SchematicWeb.pdf and has no 120 Ohm resistor after the transceiver (U404A). R420 on BG0187 is the termination resistor on the PiBridge interface.

Nicolai